US Homeland Security Secretary Janet Napolitano (L) and HHS Secretary Kathleen Sebelius (R) hold a press conference on the response to the H1N1 flu on October 28, 2009 at the Department of Health and Human Services in Washington, DC. Sebelius has already warned that demand is outstripping supply of vaccine for the novel flu strain, as 46 of the 50 states now report widespread A(H1N1) activity at an unusually early time of the year.